I want add more buttons here, how to do it ? add more buttons to the Umbraco backoffice in the publish and saving sections?

Hi there! I recommend you check out the

ContentSendingNotification

. This notification contains the menu items that are displayed in that menu. You can work with this object using a notification handler. You can find more information about notification handlers in the documentation: https://docs.umbraco.com/umbraco-cms/reference/notifications